[moderation] [kernel?] KCSAN: data-race in hrtimer_reprogram / print_cpu (9)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 052d534373b7 Merge tag 'exfat-for-6.8-rc1' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=153a162be80000
kernel config: https://syzkaller.appspot.com/x/.config?x=adb08aaa4585df88
dashboard link: https://syzkaller.appspot.com/bug?extid=28abd6e8a9f5c33cb000
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [linux-...@vger.kernel.org tg...@linutronix.de]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/475d9c925209/disk-052d5343.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1aa974d3b699/vmlinux-052d5343.xz
kernel image: https://storage.googleapis.com/syzbot-assets/046680ef4c9b/bzImage-052d5343.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+28abd6...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in hrtimer_reprogram / print_cpu

write to 0xffff888237d1f3e0 of 8 bytes by task 31060 on cpu 1:
__hrtimer_reprogram kernel/time/hrtimer.c:661 [inline]
hrtimer_reprogram+0x1a8/0x220 kernel/time/hrtimer.c:868
hrtimer_start_range_ns+0x4e3/0x660 kernel/time/hrtimer.c:1302
hrtimer_start_expires include/linux/hrtimer.h:392 [inline]
hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1968 [inline]
do_nanosleep+0x85/0x2f0 kernel/time/hrtimer.c:2044
hrtimer_nanosleep+0xe7/0x1e0 kernel/time/hrtimer.c:2100
common_nsleep+0x68/0x80 kernel/time/posix-timers.c:1350
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline]
__se_sys_clock_nanosleep+0x202/0x230 kernel/time/posix-timers.c:1373
__x64_sys_clock_nanosleep+0x55/0x60 kernel/time/posix-timers.c:1373
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888237d1f3e0 of 8 bytes by task 31102 on cpu 0:
print_cpu+0x2fb/0x640 kernel/time/timer_list.c:133
timer_list_show+0x115/0x180 kernel/time/timer_list.c:291
seq_read_iter+0x2bc/0x8f0 fs/seq_file.c:230
proc_reg_read_iter+0x114/0x180 fs/proc/inode.c:302
call_read_iter include/linux/fs.h:2079 [inline]
copy_splice_read+0x26b/0x4b0 fs/splice.c:365
do_splice_read fs/splice.c:985 [inline]
splice_direct_to_actor+0x268/0x650 fs/splice.c:1089
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x377/0x880 fs/read_write.c:1295
__do_sys_sendfile64 fs/read_write.c:1362 [inline]
__se_sys_sendfile64 fs/read_write.c:1348 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000014049576900 -> 0x00000140490d77af

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31102 Comm: syz-executor.0 Not tainted 6.7.0-syzkaller-09928-g052d534373b7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.